Make your first mod

In this tutorial you’ll make a small mod that renames a magical object and then see your new name in the game. It’s a tiny change, but it’s the whole journey every mod takes: make a change, put it in the game, check it worked, undo it.

There are two ways to do it. Pick one:

	Way 1: in your browser	Way 2: with the modding tools
What you need	A web browser on a computer, and the RSMM app	The modding tools
Typing commands	None	A few
What it can make	Items, talents, abilities, maps	Everything RSMM supports
Best for	Trying it out, quick balance changes	Bigger mods, sharing on rsmm.me

You can start with Way 1 and move to Way 2 later. The mods are the same either way.

Way 1: In your browser

The web editor runs on this website and reads the game files straight from your computer. Nothing gets uploaded and nothing needs installing.

1. Open the web editor. The first visit downloads about 12 MB, so give it a moment. It works in Chrome, Edge, Firefox and Safari on a computer, but not on a phone.

2. Choose your Ravenswatch folder. To find it, in Steam right-click Ravenswatch → Manage → Browse local files.

   Your browser will ask whether to “upload” the folder. That’s just the browser’s standard wording for letting a page read a folder. The files stay on your computer.

3. Pick an item. The Items tab opens first. Search the list on the left for an item you know from the game and click it.

4. Rename it. Leave Replace this item selected. That changes the real item rather than adding a new one. In Name, type something you’ll recognise instantly, like My Very First Item.

   Want to change what it does too? Each of the item’s numbers is listed below the name. Change one and the card preview updates as you type.

5. Check it. Press Check at the bottom. You should see Everything builds.

6. Save it as a mod. At the bottom, the mod list says New mod…. Press Create mod… and fill in the form:

   • Mod id: a short name with no spaces, like my-first-mod.
   • Name: the name people will see, like My First Mod.
   • Author: your name or nickname.

   Press Create mod. Your browser downloads my-first-mod.zip.

7. Add it to the app. Unzip the file, then follow Add a mod from a file. In short: Profiles → Open folder → move the my-first-mod folder in → Library → Add to profile.

8. Play. Press Launch Modded. In the game, open the compendium and find your item. It now has your name. 🎉

To undo it, switch the mod off in the Library, or just press Launch Vanilla.

To keep working on the mod later, open the web editor and press Open a mod folder…. More in the web editor guide.

Way 2: With the modding tools

This way you’ll write the mod yourself. It’s still only a few lines of text.

Before you start, follow Set up the modding tools. Open a terminal in the RavenswatchModManager folder with the environment switched on, so the line starts with (.venv).

1. Create the mod

rsmm new MyFirstMod

This makes a new folder, mods/MyFirstMod/, with a few starter files:

File	What it’s for
manifest.toml	The important one. Says what your mod is called and what it changes.
init.lua	A script, for mods that need one. Ours doesn’t, so you can ignore it.
config_schema.toml	Settings players can change in the app. Optional.
lang/EN.toml	Text in different languages. Optional.
README.md	A description for people reading your mod’s files.

2. Fill in the basics

Open mods/MyFirstMod/manifest.toml in a text editor. It looks something like this:

mods/MyFirstMod/manifest.toml

#:schema https://docs.rsmm.me/manifest.schema.json

[mod]
id          = "MyFirstMod"
name        = 'MyFirstMod'
version     = "0.1.0"
author      = "you"
description = ''
enabled     = true
sdk_version = ">=3.0,<4"
tags        = []
license     = ""

Change name, author and description to your own. Everything else can stay.

How to read this file

Each line is setting = value. Text goes in quotes. Lines starting with # are notes for humans and are ignored. [mod] starts the section that describes the mod itself.

3. Add your change

Add these lines to the end of the file:

multiplayer_scope = "deterministic-shared"

[[content]]
kind = "item"
mode = "replace"
id   = "Damage_Attack"
base = "Damage_Attack"
name = "My Very First Item"

Line by line:

• multiplayer_scope tells co-op players that everyone in the game needs this mod, because it changes how an item works. It belongs to [mod], so it goes right under the lines you just edited.
• [[content]] starts a block that changes one thing in the game.
• kind = "item" says that thing is a magical object.
• mode = "replace" changes the real item instead of adding a new one.
• id and base say which item. Damage_Attack is the game’s internal name for Ace of Spades.
• name is the new name the game will show.

Your whole file should now look like this:

mods/MyFirstMod/manifest.toml

#:schema https://docs.rsmm.me/manifest.schema.json

[mod]
id          = "MyFirstMod"
name        = "My First Mod"
version     = "0.1.0"
author      = "Sam"
description = "Renames Ace of Spades so I can see my mod working."
enabled     = true
sdk_version = ">=3.0,<4"
tags        = ["items"]
license     = "MIT"
multiplayer_scope = "deterministic-shared"

[[content]]
kind = "item"
mode = "replace"
id   = "Damage_Attack"
base = "Damage_Attack"
name = "My Very First Item"

Want a different item?

rsmm items list shows every item’s internal name. Or skip the typing entirely: rsmm editor opens the same editor as Way 1, and its Add to mod button writes this block into your mod for you.

4. Check it for mistakes

rsmm lint MyFirstMod

lint reads your mod and points out problems before you start the game:

• [OK] MyFirstMod at the end means it’s ready.
• [WARN] lines are suggestions, such as a missing description. Your mod still works.
• [FAIL] lines must be fixed. They say what’s wrong, and often suggest the right spelling (did you mean …?).

5. Put it in the game and play

rsmm apply
rsmm run

apply writes your mod into the game’s files, keeping a copy of each original. run starts Ravenswatch through Steam. Open the compendium and look for My Very First Item. 🎉

6. Undo it

rsmm restore --all

This puts every original file back. The game is vanilla again, and your mod is still safe in mods/MyFirstMod/ for next time.

Changing things and trying again

Edit manifest.toml, then run rsmm apply again and restart the game. Or leave this running in a second terminal, and it re-applies every time you save:

rsmm watch

Share your mod

When you’re happy with it:

1. Pack it into a single file:

   rsmm pack MyFirstMod

   This creates dist/MyFirstMod.zip.
2. Upload it on rsmm.me/publish (you’ll need an account). Every upload is scanned for malware before it appears on the site.

Prefer the command line? Create an API token on your account page, then:

rsmm publish login
rsmm publish MyFirstMod

What next?

First mod, by kindA small, working example for every kind of change: talents, enemies, maps, and more.

Example modsComplete mods to copy, including script (Lua) mods.

Modding guideEverything a manifest can do, in detail.

Build a mod with an AI assistantPoint ChatGPT, Claude or a coding agent at the real docs.